The conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put forward. First, the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil volume is analyzed. Then, a scheme using double servo valves to realize flow feedforward compensation is presented, in wh...

There is a need for a simple method to control fluid flow within microfluidic channels. To meet this need, a simple push pin with a polydimethylsiloxane (PDMS) tip has been integrated into microfluidic networks to be placed within the microchannel to obstruct flow. This new valve design can attain on/off control of fluid flow without an external power source using readily-available, low-cost ma...

In district heating stations, the heat carrier is circulated between the energy source and consumers by a pumping system. Fluid handling systems, such as pumping systems, are responsible for a significant portion of the total electrical energy use. Significant opportunities exist to reduce pumping energy through smart design, retrofitting, and operating practices. Most existing systems requirin...

Valves are important components in controlling the amount of fluid going to devices. One these types is butterfly valve (BFV) that adjusts flow by rotating disk means its shafts which usually located middle flow. Despite common usage various applications, BFV known cause a high-pressure drop. Conversely, pinch another type control device uses pinching mechanism open and close inner tube at diff...

With the increasing demand for heavy oil, core annular flow (CAF) is an economical method to transport and many researchers have explored energy-saving aspects of CAF method. This paper presents a review energy saving factors affecting saving. Among them, mainly concerns changes in pressure drop drag reduction efficiency; concern problem stability, issue restarting pipeline system, impact nozzl...

Background Theoretically, blood flow in the ascending aorta of patients with helical flow patterns, as in patients with bicuspid aortic valves (BAV), are underestimated by routine two dimensional (2D) phase contrast velocity encoding (PC-VENC). Four dimensional (4D) PC-VENC is theoretically not influenced by flow patterns. Hence, both, 2D PC-VENC and 4D PC VENC should result in similar blood fl...

A numerical study, using the volume-of-fluid method (VOF), has been made of core-annular flow in a curved pipe. We investigated two cases: core-annular flow in a 90◦ bend and in a 180◦ return bend. To verify our numerical method we first compared our results for a singlephase flow in a 90◦ bend with numerical results and experimental data given in the literature. The agreement was good. Thereaf...